FOR 259

Avicennia germinans, Black Mangrove1 Michael G. Andreu, Melissa H. Friedman, Mary M. Hudson, and Heather V. Quintana2

Family mangrove forests of Florida, it generally grows between red mangroves (Rhizophora mangle), which are found in stand- Acanthaceae, bear’s breeches family. ing waters, and white mangroves (Laguncularia racemosa), which are more of an upland species. Black mangroves Genus grow best in full sun and can reach heights of 40 to 50 feet. Avicennia was named for an Iranian philosopher and Leaves are simple and opposite and grow from 2 to 3 inches physician who lived from 980 to 1037 A.D. His alias was long. The leaf is oval and pointed, and the margins are Avicenna but his real name was Abu Ali Al-Husayn Ibn entire. The leaves appear smooth, thick, and leathery with a ‘Abd Allah Ibn Sina. dark green topside and grey to white underside. The topside of the leaves may also appear white due to the formation of Species crystals from salt that is excreted from the leaves. The bark of black mangrove is dark gray or brown. When the tree is The species name,germinans , is the Latin term for young the bark is smooth and as it matures the bark takes germination. on a thick and fissured texture. The roots produce vertical “branches” called pneumatophores, which rise from the Common Name ground and grow to a height that is just above high tide. Black Mangrove This helps the tree “breathe” during water inundation. The flowers appear at the ends of the branches and are small, The origins of the term “mangrove” are disputed among white, and fragrant with yellow centers. Fruits appear both scholars and laypersons. Some assign the origin to the throughout the year and consist of large flattened capsules Malaysian term for the trees: mangi-mangi. Others believe of seeds shaped like lima beans, which germinate while still that it originates from the Spanish term mangle or “thicket,” on the tree. first used by Gonzalo Fernández de Oviedo y Valdés in 1535 A.D. to describe the tangled thicket of branches and roots mangroves form as they grow along shorelines. Storm Tolerance This coastal tree is tolerant of waterlogged conditions and Description of salt in both the air and soil. Black mangroves, like other species of mangroves, are able to withstand major storm The black mangrove is a coastal evergreen tree native to events like hurricanes. This allows them to inhabit large Florida. It is found on mudflats and coasts throughout expanses of the storm prone coastline of Florida, where tropical and sub-tropical regions in the Americas. In the

1. This document is FOR 259, one of a series of the School of Forest Resources and Conservation Department, UF/IFAS Extension. Original publication date June 2010. Reviewed June 2019. Visit the EDIS website at https://edis.ifas.ufl.edu for the currently supported version of this publication.

2. Michael G. Andreu, associate professor of forest systems, School of Forest Resources and Conservation; Melissa H. Friedman, former biological scientist, School of Forest Resources and Conservation; Mary M. Hudson, former research assistant, School of Forest Resources and Conservation; and Heather V. Quintana, former research assistant, School of Forest Resources and Conservation; UF/IFAS Extension, Gainesville, FL 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county’s UF/IFAS Extension office. U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension. they stabilize sediments and protect the shoreline from erosion.

Figure 3. Seed emerging from the fruit of Avicennia germinans. Figure 1. Leaves and buds of Avicennia germinans. Credits: Reinaldo Aguilar, CC BY-NC-SA 2.0 Credits: Wildlife Travel, CC BY-NC-ND 2.0 Horticultural As a landscape plant, black mangroves have been planted along brackish river banks or even in upland areas. It makes a nice shade tree or a screening tree due to its thick foliage.

Medicinal The tannins in black mangrove have been used as an astringent, carrying antihemorhagic and antidiarrhetic properties.

Wildlife Organisms on the bottom of the aquatic food chain that live along the shoreline benefit from the food and shelter provided by the black mangrove. The tangled mass of roots and branches serves as a nursery ground for many organ- isms. The fish and crabs that inhabit mangroves are not only important to the structure of mangrove ecosystems, but are important for local fisheries. Despite laws that have Figure 2. Flower of Avicennia germinans. Credits: bob in swamp, CC BY-SA 2.0 been passed to protect mangroves, large areas have been cut down to make room for human development. Applications Commercial/Practical References Though the wood of black mangrove is hard, it cracks easily. Austin, D. F. 2004. Florida ethnobotany. Boca Raton, FL: However, it has been used in a variety of ways, mainly as CRC Press. posts and flooring. In the past, it was an important source Duke, J. A. 1983. Handbook of Energy Crops. Retrieved of fuel as charcoal. The bark of the black mangrove has from http://www.hort.purdue.edu/newcrop/duke_energy/ been used in the process of tanning animal skins and as Avicennia_germinans.html a black dye. The leaves, which excrete salt crystals, have been gathered as a source of salt by indigenous people. Godfrey, R. K. 1988. Trees, shrubs, and woody vines of Black mangrove flowers are also an important source of Northern Florida and adjacent Georgia and Alabama. “mangrove honey.” Athens, GA: The University of Georgia Press.

Avicennia germinans, Black Mangrove 2 Grimm, W. C. 2002. The illustrated book of trees. Mechanic- sburg, PA: Stackpole Books.

Haehle, R. J. and J. Brookwell. 2004. Native Florida plants: Low-maintenance landscaping and gardening. Lanham, MD: Taylor Trade Publishing.

Myers, R. L. and J. J. Ewel, Eds. 1990. Ecosystems of Florida. Orlando, FL: The University of Central Florida Press.

Nelson, G. 1994. The trees of Florida: A reference and field guide. Sarasota, FL: Pineapple Press.

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